The present invention relates to non-contact signal transmission apparatus that transmits power and signals in the non-contact state via the action of electromagnetic induction between a main unit and an auxiliary unit, with the auxiliary unit such as a camera being detachably attached to the main unit such as a portable information terminal that may be a cellular phone or a portable personal computer, a game machine, an AV unit, a medical unit, an industrial unit, or an environment monitoring unit.
While a cellular phone integral with a camera has been conventionally available as a portable information terminal, a cellular phone with a camera detachably attached has rarely been available.
A conventional technology for transmitting power and data via electromagnetic induction in a portable personal computer is disclosed in the Unexamined Japanese Patent Application Publication Hei 9-26834. In that disclosure, a magnetic core and a coil are provided on both the main unit and display of a portable computer at the rear of the hinge of the portable computer in order to transmit power and data via electromagnetic induction from the main unit to the display in a non-contact state, i.e., without wiring, thereby reducing wire breakage caused by stress at the hinge.
Since a conventional portable information terminal is configured as mentioned earlier, a cellular phone is integral with a camera and the camera is not detachable.
Thus, there existed a problem that it was impossible to attach a camera to a cellular phone only when necessary or detach a camera from a cellular phone integrated with a camera to use the camera for other applications.
The conventional technology shown in the Unexamined Japanese Patent Application Publication No. Hei 9-26834 is designed to transmit power and data from the main unit of a portable personal computer to the display, not to transmit power and data from the main unit of a cellular phone to a camera in a non-contact state. Thus the conventional technology cannot be applied to a technology whereby a camera as an auxiliary unit is made detachable from the main unit of a cellular phone.
The invention is intended to solve the foregoing problem and aims at providing non-contact signal transmission apparatus in which an auxiliary unit such as a camera can be attached detachably to a main unit such as a cellular phone main unit and that can reliably transmit signals and power via electromagnetic induction through a simple configuration in a non-contact state, when the auxiliary unit is attached to the main unit.
Non-contact signal transmission apparatus according to the invention is characterized in that the apparatus performs signal transmission between a main unit and an auxiliary unit via electromagnetic induction in a non-contact state, wherein a set of power cores having hollow sections are provided as a pair at corresponding positions of a main unit and an auxiliary unit, wherein a wire is wound around each of power cores (power coils) for feeding power from the main unit to the auxiliary unit and at least one set of signal cores are provided as a pair at corresponding positions of the main unit and the auxiliary unit, wherein a wire is wound around each of single cores (single coils) for transmitting signals between the main unit and the auxiliary unit, the at least one set of signal coils arranged in the hollow section of the power core.
Signal coils of non-contact signal transmission apparatus according to the invention is characterized in that the signal coils use signal cores composed of a seating and two columnar cores formed on the seating of the main unit and the auxiliary unit to wind wires so that the directions of the magnetic flux may be opposite between the two columnar cores.
Non-contact signal transmission apparatus according to the invention is characterized in that the apparatus comprises at least two sets of signal coils and arranges the signal coils so that they may be geometrically symmetric at least twice with respect to the center of a power coil and arranges two columnar cores of each signal coil at the same distance from the center of the power coil.
Non-contact signal transmission apparatus according to the invention is characterized in that the apparatus comprises at least two sets of signal coils and arranges the signal coils so that they maybe geometrically symmetric at least twice with respect to the center of a power coil and so that the distance from the center of the power coil to the center of each signal coil may be identical.
Non-contact signal transmission apparatus according to the invention is characterized in that the apparatus comprises two sets of signal coils and arranges the signal coils so that they may come at a right angle from each other and the straight line connecting the centers of coils may pass the center of the power coil.
Non-contact signal transmission apparatus according to the invention is characterized in that in a non-use state the apparatus is configured so that at least a set of signal coils of the main unit and the auxiliary unit may face each other in a dislocated state.
Non-contact signal transmission apparatus according to the invention is characterized in that the apparatus comprises power coils and signal coils integrated via mold resin into a module on the main unit and the auxiliary unit.
Non-contact signal transmission apparatus according to the invention is characterized in that the apparatus comprises an antenna for transmitting/receiving signals to/from outside on the main unit, arranges power coils and signal coils on the top of the main unit and the auxiliary unit, comprises a printed circuit board having wiring patterns to the power coil and the signal coil and an FPC (Flexible Printed Circuit) for transmitting signals to the power coil and the signal coil, and arranges chip capacitors for grounding an antenna signal propagated via the FPC to a ground for feedback at the rear surface of the printed circuit board.
Non-contact signal transmission apparatus according to the invention is characterized in that the apparatus comprises power coils and signal coils and a printed circuit board integrated via mold resin into a module shielded with a metallic coating of a predetermined thickness, excluding the chip capacitors, on the main unit and the auxiliary unit.
Non-contact signal transmission apparatus according to the invention is characterized in that the main unit is a cellular phone and the auxiliary unit is a camera.